


Strange how things change

by Whyhellothere (Crystalcatgamer)



Category: Gravity Falls
Genre: Character Study, Eventual Romance, F/M, I have so many fics now, No Smut, Sibling Incest, Teenage Dipper Pines, Teenage Mabel Pines, The Author Regrets Everything, The Author Regrets Nothing, What Have I Done, forgivemeforIhavesinned', pinecest - Freeform
Language: English
Status: Completed
Published: 2020-11-03
Updated: 2021-03-06
Packaged: 2021-03-08 17:21:55
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 3,945
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27260395
Author URL: https://archiveofourown.org/users/Crystalcatgamer/pseuds/Whyhellothere
Summary: Dipper realizes just how much he loves his sister as they grow up.
Relationships: Dipper Pines/Mabel Pines
Comments: 9
Kudos: 35





	1. Realisation

**Author's Note:**

> More fanficsss

_Dipper wonders when he started looking at his sister from great to cute to beautiful._

A year after everything that happened, her braces were finally removed. She looked nicer without them, but she was still the same great sister he had. Then just before they started high school, she went from weird weird to cute weird. She had grasped a better sense on what to say around others, and learned how to channel her emotions and excitement. She could still be herself and have friends.

Dipper changed too. He grew taller, and not in the cringy teenager way. After that, he found out that he had become way more fit than usual. He started working out, and thus didn't look like a geek. They both stopped being socially awkward and began mingling.

Well, mostly his sister.

He just liked to find a quiet spot and listen to music. Now that that Mabel didn't have braces, she would make a big show of smiling brightly at him. Dipper found it cute and often dazzling. People though so too, because Mabel had a great smile.

**That's when Dipper looked at her sister and thought, cute.**

It wasn't until they started high school however than things really changed. The twins had gotten better at fashion sense, and his sister was much better at making sweaters. Basically, less glitter and clashing colors. Mabel had grown too. She became taller, her body grew subtle curves and her limbs became long and graceful. Just like him, she stopped looking dorky and instead looked...cool.

So when they walked in, both dressed 'fashionably' - _really, Mabel just wanted to show off her latest sweater and he just gabbed the nearest clothes_ \- him with earbuds plugged in and his cap while his sister was smiling excitedly as she texted her friends. Yeah, they made a lasting impression.

For the first time, they were popular. And it wasn't just Mabel, who had been hanging out with more friends, but him too. He didn't realize it since he was acting like a loner as he navigated through students with his earbuds plugged in. It wasn't until Mabel had come running to him after school excitedly, practically yelling at him and dispelling his peaceful illusion then he knew.

"Check it out! You're popular!" His sister reported, jumping up and down. Dipper automatically grabbed her shoulders and held her in place before giving her his best _'What the hell'_ look.

"No, I'm serious. All my friends think you're hot or cool. For goodness sake, stop living in your own world!" Mabel groaned, leaning into his grip. He had scoffed at first but relented not to use his earbuds tomorrow. He walked with Mabel to school, the girl intent on proving his 'popularity'.

"Keep your ears open." His sister stage-whispered as they entered the school. Instantly for some reason all eyes were on him. Dipper looked up, scanning the faces of everyone. They looked surprised and awed.

The girls blushed and looked away while the boys looked to him hopefully. All this time he never noticed that eyes weren't just on his sister, but him as well. He shook his head, tugging his sister along. "Listen!" Mabel gushed as they walked. And Dipper did.

_"Oh my god, he doesn't have his earbuds in!"_

_"He still looks amazing though."_

_"I know! He's still pulling off the 'I'm cool' look!"_

_"He's looking! He can hear!"_

Dipper felt like something had changed as he listened to the girls whisper.

_"Holy, Dipper isn't listening to music?"_

_"Do you think we can start trying to talk to him now?"_

_"No way dude! He's out of our league. I mean, look at him and his sister!"_

He felt dizzy hearing the awe in the boys' voices. Mabel was giving him a smug _'I told you so'_ look and giggling. Dipper rolled his eyes and patted her head, feeling self-conscious at the sudden torrent of whispers.

_"Oh! Look at how cute they are! I wish I had a sibling like them!"_

_"I know right? My older brother just lazes around all day. Both of them are cute and popular! Runs in the family I guess."_

_"Dude, if Mabel wasn't Dipper's sis, I would ask her out."_

_"I know. Like, can you imagine how protective Dipper would get? They're twins after all."_

Dipper scratched his neck and walked away, trying not to hear the gossiping. Mabel skipped beside him, loving his reaction. They waited until break to meet up at the courtyard near the apple tree. He noticed people giving them a wide berth but still staring at them.

"When did this start!?" He hissed to his still smug af sister.

"From day 1, silly. You just never noticed because you're trying to be a 'loner'. All you achieved was looking cool." His sister replied, making finger quotes. Dipper sighed, leaning against the tree trunk, Mabel following suit.

"I don't know how to deal with this." He said honestly. "Just roll with it bro. Enjoy it." His twin replied, staring at the sky.

* * *

It took another week before he did and started to act like his status. He joined the track and field club, went to parties with his sister, was nice to everybody and gained even more popularity.

That was when he started noticing that they weren't just popular, but also considered one of the most eligible. Mabel would list the people she knew liked him and asked if he liked them back. The answer was no, he didn't love anyone.

_(A small part of him stirred at the words and crept towards a forbidden name, but was soon crushed.)_

He saw the way boys looked at Mabel dreamily - _how dare they_ \- and hearing them talk about how beautiful she was. Dipper studied his sister after that but only saw cute. But he could get why people thought that.

His sister had a slender figure that wasn't overly busty or fake-looking, but she wasn't flat either. She wore the necklace she roped him into making once and cute clothes. Crop tops, flowy dresses and of course, sweaters. Dipper admitted once that he liked the sweaters she made, which got him a birthday sweater and made Mabel wear them more often.

_(The same small part purred at the action, slinking back.)_

Anyway, Mabel would wear a nice sweater with her hands poking out cutely from the long sleeves, causing everyone who saw her would sigh. ~~(Including him.)~~ Dipper would hear the envy in others' tones about how close he and his sister were.

They were the perfect example of awesome siblings.

One beautiful and the other handsome. One cheerful and one cool. Both popular and kind. Not to mention their good relationship despite having grown up and being in different friend groups.

Mabel's enthusiasm and lack of public decency when it came to him was something Dipper liked and disliked. On one hand, it was nice that his sister still loved him so much, but being called from across the street because Mabel had found the ice-cream truck was embarrassing.

Dipper loved his sister and secretly enjoyed it when she popped up and gave him a surprise hug out of nowhere. He would lightly push her away, chuckling as the girl pouted. Then he would ruffle her hair and everything would be back to business as usual.

_Dipper wasn't sure when he saw his sister as beautiful._

Perhaps it had been creeping up on him all this while. But one day they were on the couch, Mabel was texting her friends while he read a book. Something thumped against his shoulder, and he looked to see his sister fast asleep on his shoulder.

Her face was like a angel as she curled up against him. **Beautiful,** was what he thought as he reached out to cup her face. Then he immediately snapped out of it and very gently carried Mabel back to their bedroom.

He tucked her in and got ready for bed. Once done he burrowed into under his sheets, reflecting on what just happened. There was a strange feeling in his chest and a tingle in his hand as he touched Mabel's cheek. Dipper curled up, banishing the word that was dancing in his heart.

**Love.**

_(He ignores it because if he doesn't, then what is he supposed to do?)_


	2. Unworthy

Dipper went through the next day like nothing happened. He nodded when Mabel thanked him for tucking her in, listened to his teachers and hung out with his friends. Then his sister smiled brightly at him before kissing his cheek and Dipper knew it was all over.

He went back home and up his room, all alone in the house with his parents out and Mabel with her friends. He put his head in his hands and rocked back and forth. When did this start?

He had gotten over his silly crush on Wendy a long time ago, and even Gideon stopped pestering his sister to be his girlfriend. Dipper clenched his fists, leaving crescent-shaped dents in his palms. He looked around at his and Mabel's room. They had continued to share a room because Mabel refused to be separated, even if it was annoying when her friends came over.

They were twins, and it was nice to keep their room and watch the memories pile up. But now he was in love with his sister - _what a sick creature he was_ \- and they had to see each other everyday. Dipper let out a shout and punched his pillow before flopping into it.

**Disgusting.**

He hated himself, hated himself for loving his twin sister when there were so many other hopefuls more than willing to be with him. He found his sister beautiful now and wanted a proper kiss, not just one on the cheek. He wanted to show the world his sister belonged to him, and not just in the familial way. He was a horrible, worthless person.

Life couldn't give him a break, could it?

Dipper ignored his sister when she came back, desperate to keep his newly-discovered secret. He muttered a quick goodnight to her, leaving the girl hanging as he climbed into bed. He felt even worse at how confused she had looked. He couldn't do anything right. That's when he realized something that seriously stretched his control and boundaries.

He was in bed, listening to music while his sister was still sleeping as long as possible on a Sunday.

"Dips?"

He turned automatically at his sister's voice and froze. Mabel was wearing one of his hoodies - _probably took it by accident_ \- and had an adorable sleepy face. The girl made grabby hands at him before deciding to cross the short distance - _too short_ \- between their beds.

She climbed in, ~~her~~ his hoodie slipping off her shoulder. Dipper swallowed, leaning back as Mabel curled up next to him. His sister would do this to leech some warmth from him or when she was feeling gloomy. A habit from childhood.

He tensed as Mabel snuggled next to him, smiling sleepily at him. Oh god, how could she be angelic and cute? Dipper shifted, staring at his sister. He was a sick, twisted monster and would not look at his sister the way he was now.

_(The small part of him, now a creature with claws whined when he looked away.)_

He wrapped Mabel in blankets before carefully creeping out of the room. He told her what happened when she woke up later calmly, like it didn't matter one bit.

_(The creature growled, slashing his heart.)_

* * *

"Hey Mabel."

They were hiking and had stopped in a clearing to eat. His sister had been whining about getting fresh air and how they were never spending time together until Dipper finally relented.

"Do you like, like anyone?" He finally choked out, watching his sister. Mabel got a wistful expression on her face and rested her chin on her knees.

"I do, but it's really stupid. I'll never get together with him. He doesn't love me back." The girl replied, looking into nowhere. Dipper was relieved - _stupid, he shouldn't be_ \- and confused as to who would not love his sister. Everyone did, even him.

"What about you?" The girl brightened instantly, rounding on him. "Same as you. I've known her forever, and she kinda crept up on me." Dipper said slowly, trying to avoid eye-contact. His sister paused for a moment and he could practically see the gears turning.

"But you're amazing! How could she not?" Mabel protested, gesturing to him.

"So are you."

The words came out huskier then he expected and he was aware of how close Mabel was. The girl had shifted over in her outburst. For a moment they stared into each others' eyes, their foreheads almost touching.

"That's nice of you to say, bro." Mabel smiled and hugged him tightly. Dipper froze and hesitantly returned it, cursing himself internally.

_(The creature snarled in disappointment and skulked back into his heart.)_

A year passed. Dipper decided to stop ignoring his sister but still maintain a respectable distance. Fast forward and now they were starting college. Still in the same class by some mysterious freak of nature. And no, his feelings for his sister had not diminished. He couldn't, because he had fallen for her despite all her bad points that he knew as her brother.

On the first day of college Dipper woke up to his sister's excited shouts. He got dressed and half-listened to his sister's chatter as they walked to school. Dipper watched her meet up with her friends, blending seamlessly into the crowd. He let out a sigh and headed for his locker.

"Hello there." He paused as a girl walked up to him, a few other girls trailing behind. One look and Dipper knew that they were the popular girls in this school. Not that they held a candle to his sister, of course.

"Want me to show you around? I'm Elena." Elena offered, twirling her hair. He could feel eyes on them, both awed and envious. "No thanks. But I'm Dipper." He plastered on a smile.

It was worth it when Elena's eyes bugged out, clearly unused to refusal. A mutter broke among the crowd as Dipper closed his locker. Instantly Elena's expression was schooled and a calculating look took over. Damm it, she was one of those types.

"Excuse me! Moving through!" Dipper blinked as his sister suddenly burst out of the crowd. "What are you doing brobro! We need to get to class!" Mabel chided, ignoring Elena and her entourage.

She had dressed well today, having wanted to make a good expression. It worked, and Dipper didn't doubt his sister looked more beautiful then Elena. Half the boys were staring at her now. 

"Hello, are you his sister?" Elena cleared her throat, obviously scrambling for control. "Oh, you were here? Sorry! But yeah, I'm Mabel, Dipper's twin sister!" Mabel said cheerfully, flashing a dazzling smile.

Elena froze and the two locked in a staring battle. Dipper sighed, wondering why this was happening. His sister would win, since Elena's reputation had already been damaged by his rejection earlier. Finally Elena looked away, trying to play it cool.

"It was nice to meet you! Bye!" Mabel said brightly, but there was no missing the smugness in her eyes. Dipper yelped as his sister grabbed him, pulling him to their classroom.

"Great job bro. You just made me shift the whole school's hierarchy and it's been 10 minutes since we entered school." Mabel complained as they took their seats. "Hey, I could have walked away!" He argued back.

"Hmph. I saw the girl's eyes. She was going to take you. I couldn't let that happen, right?" His sister looked so worried that he might actually like Elena.

"No worries. You know I hate girls like her." He replied, ruffling her hair. Mabel brightened immediately and started talking about how great their new school was. Dipper watched, smiling internally.

_(The creature purred at the events, focusing on Mabel's possessiveness.)_

Something else happened a few weeks later.

"Dipper! You've got to see this!" One of his friends called, running over. "It's your sister!" Instantly Dipper was up, following his friend through the hallways. The crowd parted for him and to show something that made his blood boil.

Mabel was staring defiantly up at a bulky boy called Thomas, who everyone knew was rich and had been eying Mabel. Thomas had his sister pushed against a wall and was leering at her.

_(The creature hissed in fury, sharpening its claws.)_

"How about it? You'll have everything you want if you date me." Thomas crooned, looming over his twin. Mabel gave him the finger paired with a nasty look that sparked the crowd.

"Why you-" Thomas moved to hit Mabel.

Immediately Dipper was there and caught his fist. "Is something wrong?" Dipper asked, his words laced with bloodlust. "U-um." Thomas whimpered, shrinking back as Dipper stared him down. He gripped the boy's fist hard enough to make him wince.

"If you ever touch my sister again," Dipper began, his voice slow and deadly. "I will rip you apart and feed you to the dogs." Mabel popped out from behind him and glared at Thomas.

"Now scram." His sister snarled in a rare display of anger. Thomas ran off, shaking in fear. The crowd gaped at them, disturbed by their rage. They quickly dispersed as Dipper turned on them, muttering among themselves.

"Are you alright?" He immediately checked his sister over, looking for bruises and torn clothing. "Don't worry Dipper. That dude didn't do anything." Mabel patted his cheek affectionately. Dipper let out a sigh of relief, leaning on his sister's shoulder.

"Thanks bro." Mabel continued, giving him a peck on the cheek. Dipper hugged his sister tightly and stuck close as they went back to class.

Rumors followed them for weeks after, but it was fine as long as his sister was safe and sound.

_(The creature curled up, pleased with his actions.)_


	3. Together

**Notes for the Chapter:**

> HOLY SHIT I FINISHED THIS AVDKEBSOWNISBAGHA  
> I actually had no idea how to, which was why I stopped writing for this, but now I managed to wrap it up and I'm so proud. Thanks to Tears_red for giving me the push I needed to finish it, might have just never touched it again otherwise.

Dipper sipped his drink, watching the party. It was graduation day, and the student council really knew how to throw a celebration. Parties had always fascinated him, in the fact that he liked to watch them. Not like Mabel, who was the life of them.

The disco hanging above painted everyone a variety of colors, making them look otherworldly. He watched the mix of moving bodies and shiny clothes. He had always wondered how people could drink burning alcohol, dance like no one was watching then wake up hungover as hell but still say _'Worth it'._ He still wouldn't join the dance floor for anything.

"Dipper~" He jumped as Mabel draped herself on him, clearly drunk. "Sis, I told you not to drink so much." He sighed, glad that the dim light hid his blush. He carefully disentangled himself from Mabel's grip and led her out, waving goodbye to some of her friends.

"But you'll always be there to catch me, right Dips? You're the best." Mabel giggled as he helped her into the car.

**(The monster cooed at the trust.)**

They got back home without incident and Dipper helped his sister into her bed, placing some aspirin with water on the bedside table for when Mabel woke up. The girl propped herself up and suddenly locked her arms around his neck, pulling him down onto the bed. Dipper started and pulled away, but Mabel held him tight ~~maybe he wanted the touch, so what.~~

"I love you Dips." Mabel whispers, full of affection and he freezes. For a moment Mabel's eyes were so clear that he was kissing her suddenly, years of passion poured into the single action. Then the smell of alcohol hit him and he wrenched away, running to the bathroom.

**(The monster _screams_.)**

He locked himself in, panting as he checked if Mabel followed. Then he started panicking. What had he just done? He was a sick, sick monster who had taken advantage of his drunk sister.

Oh god, what if she remembered the next day? She would hate him forever. He would rather live with his feelings for the rest of his life than handle that. Dipper has nothing but disgust for himself, for being so selfish.

If Mabel remembered, she would hate him forever. Dipper deserved it. He rests his head in his hands, shaking. After a while he brushes his teeth, quietly leaving the bathroom. He peeks into the bedroom to find his sister fast asleep. He tucked her in, turned off the light and curled up on his own bed. When tomorrow came, then he would know.

* * *

Mabel woke up half-tangled in her bedsheets. She struggles free, looks around sleepily and spots her brother still sleeping on his bed. The memories fill her.

The party. Getting drunk. Dipper bringing her home. Dipper kissing her.

Mabel blinked, wondering if she had hallucinated last night. She had fallen for her brother a long time ago, when they turned 15. They were popular and riding the good life, enjoying their newfound status.

Then the day a girl tried to hit on her brother, jealously roared within her. Dipper was her twin brother, her everything. They had gone through everything together. That was the day she realized she was in love with her brother.

She was horrified, desperately trying to check that she hadn't fallen for her twin. She had. And Mabel loves every part of Dipper, the small smiles just for her, late nights spent drinking hot cocoa and watching the snow fall.

So she keeps her emotions bottled up, never wanting the boy to know. Dipper would hate her forever if he knew, be disgusted with her. And she had rather die than face that.

There were a few close calls when Mabel almost confessed, when she dared hope that Dipper felt the same for her. Stupid, she knew, but she couldn't crush the hope in her. But Dipper hadn't been drunk when they kissed, even returning her affection.

So the hope rises in her, curling up in her chest and urging her to go for it. She gets ready and returns back to the bedroom to find Dipper wide awake.

"Dipper!" She brightens, skips forward and freezes as Dipper flinches. "D-do you remember last night?" The boy asks softly and Mabel nods. Dipper seems to crumple and Mabel feels doubt tug at her as she sat down next to the boy hesitantly. Then their eyes meet and she realizes Dipper had been going through the same thing she had.

"Dipper." She says gently, a smile tugging her lips upwards. "I love you too." And the way Dipper's eyes widen as hope lit a fire in them was the greatest thing she could ever ask for.

"Really?" There's a fragileness in the boy's voice as he stared at her. Mabel grins, eyes shining as she nodded. "You're not disgusted that we're twins?" Dipper asked, disbelief and awe in his voice.

"I hated myself at first, but I love you and you love me. And that's all that really matters." Mabel explained, reaching out to cup Dipper's cheek. He relaxes into her touch, smiling at her in a way he hasn't in a long time.

And maybe there'll be bumps as they keep their relationship secret, maybe there'll be people they reveal their status to, maybe it's not taken kindly. But they have always had each other, and they weren't going to stop now.

Mabel loves Dipper and Dipper loves Mabel. They're twins and people says it's disgusting but they love each other, past the boundaries of family.

And that's all that really matters.

**Notes for the Chapter:**

> So yeah, that's my take on incest. Honestly, if both sides agree to it and truly love each other romantically, I don't really see a big problem with it. Yeah, they're related and everything but it's just DNA. Don't let that define you. It's just my opinion tho, not gonna force it on anyone if they don't like it


End file.
